Lining apparatus



United States Patent 3,086,290 LINING APPARATUS Emmett L. Kuehl, 2969 Kincaid, Overland, M0. Filed Apr. 6, 1961, Ser. No. 101,240 3 Claims. (Cl. 33-41) This invention relates to lining apparatus. It has particular, but not exclusive, application to the lining of blackboards.

It is desirable for the aid of student and teacher alike, that blackboards be provided with lines to serve as guides in writing. At the same time, the lines should be unobtrusive, so that when the blackboard is used for drawings or indicia for which the lines serve no purpose, the lines do not interfere with the portrayal.

It has been the practice in many schools, over a period of a great many years, to line blackboards with ink. The apparatus which has been used heretofore has been cumbersome, and the task has been inordinately time consuming. I ll 1 One of the objects of this invention is to provide apparatus by which blackboards can be lined quickly and easily.

Another object is to provide such a device which has application to the lining of various kinds of surfaces having a structural element of reference at right angles to the surface to be lined.

Still another object is to produce such a device which is easy to manufacture, compact, economical to use, sturdy, dependable and durable.

Other objects will become apparent to those skilled in the art in the light of the following description and accompanying drawing.

In accordance with this invention, generally stated, lining apparatus is provided which includes a carriage having bearing surface means adapted to engage an element of reference, such as the chalk rail of a blackboard. A staff, extending from and carried by the carriage, is substantially perpendicular to the bearing surface means. The staff carries a bracket, mounted to slide along the staff, and provided with clamping means for clamping the bracket to the staff selectively at a multiplicity of locations. Spacing means are mounted adjacent either end of the staff, and each of the spacing means has a hearing surface adapted to bear on the surface to be lined, and which permits it to move smoothly along the surface to be lined. The carriage bearing surface means are ofiset away from the plane of the surface to be lined;

Preferably, the spacing means consist of at least three rotating disks, the axes of rotation of which are parallel with the long axis of the staff, and the perimeters of which at their bearing points in use, define a plane coincident with the surface being lined.

Preferably, also, the bearing surface of the carriage is provided by a pair of rollers of substantial axial length, mounted to rotate on axes perpendicular to the plane of the surface to be lined, and with their effective bearing surface in use perpendicular to the long axis of the staff.

Preferably, also, the marking means-holding bracket is arranged to hold rigid-bodied tubes of ink, provided with felt or similar applicators. In the preferred embodiment shown, the bracket is made with two, integral, tube holders. While this is an advantageous arrangement, the number of tubes held, and therefore the number of lines made at one time, may be made more or less.

In the drawing,

FIGURE 1 is a view in perspective showing a liner, constructed in accordance with one illustrative embodiment of this invention, in use;

FIGURE 2 is a sectional view taken along the line 2-2 of FIGURE 1;

mi- 1C6 FIGURE 3 is a view in rear elevation of the device shown in FIGURES 1 and 2;

FIGURE 4 is a sectional view taken along the line 4-4 of FIGURE 3; and

FIGURE 5 is a sectional view taken along the line 5--5 of FIGURE 3.

Referring now to the drawing for one illustrative embodiment of this invention, reference numeral 1 indicates the complete liner. As shown in FIGURES 1 and 2, the liner 1 of this embodiment is adapted to rest on a chalk rail 2 and against a blackboard 3. The expression blackboard is used herein to embrace any vertical writing surface with a horizontal rail, whether it be slate, glass, or whatever.

The liner 1 of this invention includes a carriage 5, a staff 15, a tube holding bracket 20, lower spacer means 30 and upper spacer means 35.

In the illustrative embodiment shown, the carriage 5 consists of a tubular inverted U-shaped stand, with legs 6, in the ends of which threaded studs 14 are secured to project axially. A nut 7 is drawn up tightly on each stud 14-, against the end of the leg 6. The nut 7 serves as the upper clamping surface for the inner race of ball bearing 31 in the center of each of fiber disks 32 which constitute the lower spacer means 30. p

A second spacer clamping nut 8, drawn up tightly against the underside of the inner race, holds each of the disks 31 accurately in position.

In the embodiment shown, an upper roller bracket nut 9 is drawn up, on the stud 14, against the lower spacer clamp nut 8. A roller bracket 10 is clamped securely between the upper roller bracket nut 9 and a lower roller bracket nut 11.

The rollerbracket 10 is a simple angle shape, and, as

shown particularly in FIGURE 2, its depending leg is parallel with the plane of the surface to be lined. The depending leg carries a spindle, rigidly secured to the leg and threaded at its outer end. A roller 12 is mounted for free rotation on the spindle, and is maintained on the shaft by a cap nut 13, taking on to the threaded end of the spindle.

In this embodiment, the staff 15 is rigidly secured, as by welding or brazing, to the center of the carriage 5, parallel with the axes of the legs 6 and oppositely directed. The staif 15 is also tubular, and is provided along its length with locating indicla, which are here shown as annular grooves 16. A threaded stud is set securely in the upper end of the staff, projecting from the staff along its central axis. An upper spacer clamp nut 17, on the threaded stud, is drawn down against the end of the staff. The inner race of ball bearings in the center of a fiber disk 36 constituting the upper spacer means 35, is clamped between the nut 17 and a cap nut 18.

The bracket 2! in the embodiment shown, includes a tubular sleeve 21, closely but freely slidably mounted on the staff 15; a U-shaped piece 22, the central portion of which is curved to conform to the sleeve 21 and is rigidly secured thereto, and the outer ends of legs 23 of which are bent to form tube holders 24; and set screws 25, 26 and 27. The set screw 25 serves to maintain the bracket 20 at any desired location. The superposition of the center portion of the piece 22 on the sleeve 21 gives suflicient wall thickness to provide for adequate threading for the set screw 25. The set screws 26 and 27, which serve to hold ink tubes 28, are screwed into threaded passages, which, in the embodiment shown,'a're augmented by the securing of an additional piece of metal 29 to the outer side of each holder 24.

2 The ink tubes 28, in the embodiment shown, are

commercially available, felt tipped marking ink tubes. Their construction, except as it relates to the construction of the tube holders, forms no part of this invention. An

illustrative example of a suitable, commercially available, ink tube is shown in Design Patent No. 189,896.

In use, the liner is positioned with the rollers 12 resting on the chalk rail2, as indicated in FIGURES 1 and 2, with the spacing disks 3?. and 36 against the face of the blackboard. The tubes 23 are aligned so that their felt tips will touch the blackboard with the same pressure. The felt tips of the tubes are commonly made in such a way, that when turned one way they produce a thick line, e.g., one-fourth inch, and when rotated through 90", produce a relatively thin line, e.g. one-eighth inch. Normally, they should be oriented in the same direction. Preferably, the tubes are inserted far enough so that when the arms 23 of the bracket 25 are parallel with the surface of the blackboard, and the tubes are perpendicular thereto, the felt is in the proper position. In this position, the liner will operate in either direction of travel. The bracket is then positioned in the desired location along the staff, preferably at one of the grooves 16, and the set screw 25 is tightened to hold the bracket in position. It is then only necessary to move the liner lightly along the chalk rail with the rollers 12 in engagement with the chalk rail and the disks 32 and 36 in engagement with the board. The inking tubes will make a suitable line, with no appreciable pressure on them.

In the embodiment shown, the grooves 16 are six inches apart, the tips of the felts (i.e. the central axes of the holders 24) are three inches apart, center to center, and the sleeve 21 is two inches long. If the lower edge of the sleeve 21 is placed at an upper mark 16 for one set of lines, and is dropped to the next mark for the second set of lines, the lines will be three inches apart. If, instead, the upper edge of the sleeve 21 is placed contiguous the upper mark for the production of the second set of lines, the lines will be one and a half inches apart.

The ordinary commercial type of inking tube is said to be capable of marking three to five thousand lineal feet of line. Since a classroom of ordinary size, with blackboards on three sides, takes in the neighborhood of five hundred lineal feet of lining, with the lines three inches apart, two tubes will suffice for six to ten rooms.

While the absolute dimensions of the device are not of essential importance, the device of the illustrative embodiment is approximately thirty-four inches high. The provision of an effective elongated bearing surface for the carriage is of great importance. It is also a matter of importance to provide a wide bearing surface, so that chalk rails of varying widths can be accommodated by the same carriage bearing surface. In the illustrative embodiment, the surface is provided by the lines of contact of the rollers 12, which, in the illustration, are about two inches long.- The rollers may be made of hard wood, plastic, or any other suitable material which is dimensionally stable and hard enough to resist wear. It is to be noted that the lateral spacing of the lower spacing disks and the rollers is the same, and that, in the embodiment shown, they are spaced only about four inches, center to center. It has been found that this is suflicient to give a stable base, and yet to provide a compact liner.

The spacing disks rotate freely upon their ball bearings. It is to be noted that, there being three disk-s, their points of contact with the blackboard always define a plane common to the plane of the blackboard. In the embodiment shown, the disks are made of fiber of the type used in making silent gears. It can be seen, however, that any suitable material may be used, as long as it is dimensionally stable and hard enough to resist wear, without scratching the surface to be lined.

The staff and carriage of the device shown and described are made of inch O.D. copper tubing, chromium plated. However, it can be seen that numerous other materials are available and suitable. The carriage and staff can be made in one piece of aluminum, or it can be fabricated of steel or plastic, for example.

Numerous variations in the construction of the device, within the scope of the appended claims will occur to those skilled in the art in the light of the foregoing disclosure. By way of example, the device in its simplest form could consist of an inverted L-shaped or Z-shaped carriage of plastic or the like, a horizontal leg of which can serve as the lower spacing means and the lower edge of the depending vertical (in the case of the L-shaped), or lower horizontal (in the case of the Z-shape) leg as the carriage bearing surface. A shaft can extend vertically from the carriage, and be provided at its top with a fixed spacer block. This embodiment has many disadvantages, but those skilled in the art can perceive embodiments intermediate the simplest and the preferred in the light of this disclosure.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. Lining apparatus, for forming lines on a blackboard having a chalk rail, comprising a carriage; a tubular staff extending upwardly from and carried by said carriage; a marking means carrying bracket slidably mounted on said staff, said marking means carrying bracket comprising a U-shaped piece with upper and lower legs projecting away from said staff, said legs being bent circularly at their ends to form tube holders; means for selectively clamping said bracket to said staff, and spacing disks mounted on said carriage on axes parallel with the staff, said carriage having spaced rollers adapted to bear on the chalk rail, said rollers being mounted for rotation on axes perpendicular to the blackboard and to the long axis of the staff, and being axially long as compared with their diameters.

2. The apparatus of claim 1, wherein the marking means carrying bracket includes a sleeve slidably mounted on said staff, and the staff is provided with markings evenly spaced along its length, the spacing between said markings being three times the axial length of the said sleeve and twice the center to center distance between the said tube holders.

3. Lining apparatus comprising an inverted U-shaped tubular carriage having studs extending downwardly from the ends of the depending legs of said U, spacing disks revolvably mounted on said studs, and rollers mounted on spindles carried by brackets mounted on said studs, said spindles projecting parallel with one another and perpendicularly to the said studs; a staff carried by said carriage, projecting vertically from the center thereof and in the opposite direction from said carriage legs, said staff having regularly spaced indicia along its length and a stud projecting from its upper end; a marking means-carrying bracket slidably mounted on said staff, said bracket comprising a tubular sleeve embracing said staff, a unitary U-shaped tube holding piece secured to said sleeve with the legs of the U-shaped piece projecting away from the said staff and the ends of said legs curled to form tube holders, said sleeve being in axial extent one-third of the distance between the successive indicia on the staff, and the center to center distance of the tube holders being one-half the said distance between successive indicia; and a spacing disk rotatably mounted on the stud projecting from the said staff.

References Cited in the file of this patent UNITED STATES PATENTS 561,585 Harris June 9, 1896 798,250 Ballance Aug. 29, 1905 864,326 Nadoolman Aug. 27, 1907 1,186,716 Walker June 13, 1916 1,835,822 Stutzenstein Dec, 8, 1931 1,970,476 Schutze Aug. 14, 1934 2,660,791 Howell et a1 Dec. 1, 1953 

1. LINING APPARATUS, FOR FORMING LINES ON A BLACKBOARD HAVING A CHALK RAIL, COMPRISING A CARRIAGE; A TUBULAR STAFF EXTENDING UPWARDLY FROM AND CARRIED BY SAID CARRIAGE; A MARKING MEANS CARRYING BRACKET SLIDABLY MOUNTED ON SAID STAFF, SAID MARKING MEANS CARRYING BRACKET COMPRISING A U-SHAPED PIECE WITH UPPER AND LOWER LEGS PROJECTING AWAY FROM SAID STAFF, SAID LEGS BEING BENT CIRCULARLY AT THEIR ENDS TO FORM TUBE HOLDERS; MEANS FOR SELECTIVELY CLAMPING SAID BRACKET TO SAID STAFF, AND SPACING DISKS MOUNTED ON SAID CARRIAGE ON AXES PARALLEL WITH THE STAFF, SAID CARRIAGE HAVING SPACED ROLLERS ADAPTED TO BEAR ON THE CHALK RAIL, SAID ROLLERS BEING MOUNTED FOR ROTATION ON AXES PERPENDICULAR TO THE BLACKBOARD AND TO THE LONG AXIS OF THE STAFF, AND BEING AXIALLY LONG AS COMPARED WITH THEIR DIAMETERS. 